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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_UnderlyingSinkCallbackHelpers_h
+#define mozilla_dom_UnderlyingSinkCallbackHelpers_h
+
+#include "mozilla/Maybe.h"
+#include "mozilla/Buffer.h"
+#include "mozilla/HoldDropJSObjects.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/UnderlyingSinkBinding.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsISupports.h"
+#include "nsISupportsImpl.h"
+#include "nsIAsyncOutputStream.h"
+
+/*
+ * See the comment in UnderlyingSourceCallbackHelpers.h!
+ *
+ * A native implementation of these callbacks is however currently not required.
+ */
+namespace mozilla::dom {
+
+class WritableStreamDefaultController;
+
+class UnderlyingSinkAlgorithmsBase : public nsISupports {
+ public:
+ NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+ NS_DECL_CYCLE_COLLECTION_CLASS(UnderlyingSinkAlgorithmsBase)
+
+ MOZ_CAN_RUN_SCRIPT virtual void StartCallback(
+ JSContext* aCx, WritableStreamDefaultController& aController,
+ JS::MutableHandle<JS::Value> aRetVal, ErrorResult& aRv) = 0;
+
+ MOZ_CAN_RUN_SCRIPT virtual already_AddRefed<Promise> WriteCallback(
+ JSContext* aCx, JS::Handle<JS::Value> aChunk,
+ WritableStreamDefaultController& aController, ErrorResult& aRv) = 0;
+
+ MOZ_CAN_RUN_SCRIPT virtual already_AddRefed<Promise> CloseCallback(
+ JSContext* aCx, ErrorResult& aRv) = 0;
+
+ MOZ_CAN_RUN_SCRIPT virtual already_AddRefed<Promise> AbortCallback(
+ JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
+ ErrorResult& aRv) = 0;
+
+ // Implement this when you need to release underlying resources immediately
+ // from closed/errored(aborted) streams, without waiting for GC.
+ virtual void ReleaseObjects() {}
+
+ protected:
+ virtual ~UnderlyingSinkAlgorithmsBase() = default;
+};
+
+// https://streams.spec.whatwg.org/#set-up-writable-stream-default-controller-from-underlying-sink
+class UnderlyingSinkAlgorithms final : public UnderlyingSinkAlgorithmsBase {
+ public:
+ NS_DECL_ISUPPORTS_INHERITED
+ NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(
+ UnderlyingSinkAlgorithms, UnderlyingSinkAlgorithmsBase)
+
+ UnderlyingSinkAlgorithms(nsIGlobalObject* aGlobal,
+ JS::Handle<JSObject*> aUnderlyingSink,
+ UnderlyingSink& aUnderlyingSinkDict)
+ : mGlobal(aGlobal), mUnderlyingSink(aUnderlyingSink) {
+ // Step 6. (implicit Step 2.)
+ if (aUnderlyingSinkDict.mStart.WasPassed()) {
+ mStartCallback = aUnderlyingSinkDict.mStart.Value();
+ }
+
+ // Step 7. (implicit Step 3.)
+ if (aUnderlyingSinkDict.mWrite.WasPassed()) {
+ mWriteCallback = aUnderlyingSinkDict.mWrite.Value();
+ }
+
+ // Step 8. (implicit Step 4.)
+ if (aUnderlyingSinkDict.mClose.WasPassed()) {
+ mCloseCallback = aUnderlyingSinkDict.mClose.Value();
+ }
+
+ // Step 9. (implicit Step 5.)
+ if (aUnderlyingSinkDict.mAbort.WasPassed()) {
+ mAbortCallback = aUnderlyingSinkDict.mAbort.Value();
+ }
+
+ mozilla::HoldJSObjects(this);
+ };
+
+ MOZ_CAN_RUN_SCRIPT void StartCallback(
+ JSContext* aCx, WritableStreamDefaultController& aController,
+ JS::MutableHandle<JS::Value> aRetVal, ErrorResult& aRv) override;
+
+ MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> WriteCallback(
+ JSContext* aCx, JS::Handle<JS::Value> aChunk,
+ WritableStreamDefaultController& aController, ErrorResult& aRv) override;
+
+ MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> CloseCallback(
+ JSContext* aCx, ErrorResult& aRv) override;
+
+ MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> AbortCallback(
+ JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
+ ErrorResult& aRv) override;
+
+ protected:
+ ~UnderlyingSinkAlgorithms() override { mozilla::DropJSObjects(this); }
+
+ private:
+ // Virtually const, but are cycle collected
+ nsCOMPtr<nsIGlobalObject> mGlobal;
+ JS::Heap<JSObject*> mUnderlyingSink;
+ MOZ_KNOWN_LIVE RefPtr<UnderlyingSinkStartCallback> mStartCallback;
+ MOZ_KNOWN_LIVE RefPtr<UnderlyingSinkWriteCallback> mWriteCallback;
+ MOZ_KNOWN_LIVE RefPtr<UnderlyingSinkCloseCallback> mCloseCallback;
+ MOZ_KNOWN_LIVE RefPtr<UnderlyingSinkAbortCallback> mAbortCallback;
+};
+
+// https://streams.spec.whatwg.org/#writablestream-set-up
+// Wrappers defined by the "Set up" methods in the spec.
+// (closeAlgorithmWrapper, abortAlgorithmWrapper)
+// This helps you just return nullptr when 1) the algorithm is synchronous, or
+// 2) an error occurred, as this wrapper will return a resolved or rejected
+// promise respectively.
+// Note that StartCallback is only for JS consumers to access the
+// controller, and thus is no-op here since native consumers can call
+// `ErrorNative()` etc. without direct controller access.
+class UnderlyingSinkAlgorithmsWrapper : public UnderlyingSinkAlgorithmsBase {
+ public:
+ void StartCallback(JSContext* aCx,
+ WritableStreamDefaultController& aController,
+ JS::MutableHandle<JS::Value> aRetVal,
+ ErrorResult& aRv) final {
+ // Step 1: Let startAlgorithm be an algorithm that returns undefined.
+ aRetVal.setUndefined();
+ }
+
+ MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> CloseCallback(
+ JSContext* aCx, ErrorResult& aRv) final;
+
+ MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> AbortCallback(
+ JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
+ ErrorResult& aRv) final;
+
+ virtual already_AddRefed<Promise> CloseCallbackImpl(JSContext* aCx,
+ ErrorResult& aRv) {
+ // (closeAlgorithm is optional, give null by default)
+ return nullptr;
+ }
+
+ virtual already_AddRefed<Promise> AbortCallbackImpl(
+ JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
+ ErrorResult& aRv) {
+ // (abortAlgorithm is optional, give null by default)
+ return nullptr;
+ }
+};
+
+class WritableStreamToOutput final : public UnderlyingSinkAlgorithmsWrapper,
+ public nsIOutputStreamCallback {
+ NS_DECL_ISUPPORTS_INHERITED
+ NS_DECL_NSIOUTPUTSTREAMCALLBACK
+ NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(WritableStreamToOutput,
+ UnderlyingSinkAlgorithmsBase)
+
+ WritableStreamToOutput(nsIGlobalObject* aParent,
+ nsIAsyncOutputStream* aOutput)
+ : mWritten(0), mParent(aParent), mOutput(aOutput) {}
+
+ // Streams algorithms
+
+ already_AddRefed<Promise> WriteCallback(
+ JSContext* aCx, JS::Handle<JS::Value> aChunk,
+ WritableStreamDefaultController& aController, ErrorResult& aRv) override;
+
+ // No CloseCallbackImpl() since ReleaseObjects() will call Close()
+
+ already_AddRefed<Promise> AbortCallbackImpl(
+ JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
+ ErrorResult& aRv) override;
+
+ void ReleaseObjects() override;
+
+ private:
+ ~WritableStreamToOutput() override = default;
+
+ void ClearData() {
+ mData = Nothing();
+ mPromise = nullptr;
+ mWritten = 0;
+ }
+
+ uint32_t mWritten;
+ nsCOMPtr<nsIGlobalObject> mParent;
+ nsCOMPtr<nsIAsyncOutputStream> mOutput;
+ RefPtr<Promise> mPromise; // Resolved when entirely written
+ Maybe<Buffer<uint8_t>> mData;
+};
+
+} // namespace mozilla::dom
+
+#endif